Question

What is the default value of accumulator in booth’s multiplication of two 4-bit binary numbers?

(a) 0

(b) 1

(c) 0000

(d) 00000

The question was asked at a job interview.

This interesting question is from Booth’s Algorithm in section Computer Arithmetic of Computer Fundamentals

Answer 1

Right answer is (d) 00000

Easiest explanation: The correct answer is d because in case of Booth’s algorithm an extra bit is always added to the binary numbers.  The 4-bit binary numbers become 5-bit numbers after adding the extra bit. Accumulator is always assigned 0 bits of the order of the binary numbers whose multiplication is to be performed.